Swaziland - Taxation

Swaziland has a progressive personal income tax system with rates
ranging from 0% to 30%. There are no local taxes. Corporate income tax
is levied at a flat rate of 37.5%, up from 30% in 1990's. There
are no capital gains tax, tax on dividends from companies paid to
residents, or estate taxes. Swaziland has double taxation treaties with
several countries including South Africa. The standard rate for the
sales tax was increased from 12% to 14% in 2003, with higher rates for
items like alcohol and tobacco. Exempted from sales tax are fresh
foodstuffs, drugs, medicines, furniture and building supplies. In 2003,
the government was considering replacing the sales tax with a
value-added tax (VAT) system.

Will the perpetual increase of tax for substances like alcohol and tobacco harm or help Swazis? We all know that such substances are mostly taken habitualy,and in the long run, not voluntarily and they are highly addictive. Then, what if the people, because of what I have already mentioned, decide- not actually decide- but are forced to give much of their income to purchasing these substances at the opportunity cost of their families being hungry and their children not being sent to school?
What measures does the government use in undertaking such and what is the aim? Could it be to discourage the consumption of such or for some gain? I suppose that the gorvnment should measure the elasticity of such to see if the overall result is the nation being helped or harmed. Thanks!!